Electric instrument handle



Al1g- 7, 1934- R. c. ANGELI.

ELECTRIC INSTRUMENT HANDLE Filed April lO I, .Nimm

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UNITED STATES @PATENT oFFIcE ELECTRIC INSTRUMENT HANDLE' Robert C. Angell, Prine e Bay, N. Y., assignor to The S. S. White Dental Manufacturing Company, a corporation of Pennsylvania Application April 10, 1930, Serial No. 443,026

' 4 Claims.

My invention relates particularly to that class of electrical heating devices that comprise a handle having a heating element arranged to induct heat into an instrument that may be 'l held thereby and utilized for various purposes such as the drying of root canals of a tooth to be lled, cauterizing, bleaching or in working thermal plastics, etc., and is especially directed to operative means Within the handle which is automatically tion of the handle in as may be.

- The principal object .to provide an implement in which actuated by manipulawithdrawing and replacing it with respect to its eect closing or opening o holder or -support to i the electric circuit,

s of my invention are heat electriaintained at a predemay be utilized with safety and comfort in performing various operations.

Other objects of my invent ion are to provide a heat directing implement in which the heat is concentrat to the heating ins p Further objects of m vide an electric implem mechanism is so disp My invention further that is substantially pockets or cre taken apart an mum of sterilizing fluid My invention compreh ises an end with a h lably provided electrical and being instrumentnected thereto remote ed and retaine trument by which the heat is directed to the point where it is to be uti vices and that may be d be sterilized with but a minihandle unit, a sw d in close proximity lized. y invention are to proent in which theV switch osed and arranged as to be actuated axially to clos ltric circuit by movement l.or into its holder or supper e and open the elecof the handle out oi includes an implement ree from dust-catching readily tending to cling thereto. ends an electric instrua switchv in which the by the shell or casing,

d frees said parts for inrepair and replacement. orm of my invention as hereinafter electric implement comtch unit therein, an t attached thereto and unit removably engaged -holding unit, the instrument-holding unitbeing provi eating ele rected therethrough and c ded at its forward havingA leads dionnected with suitcontacts at its `rear end,

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further provided with an elongated carrying thimble removablyy confrom said heating ele- .ment but having contact 'with the shell enclosing said heating element, so that the heat Airom said heating element will be conducted forwardly directlyv to the instrument carried by saidfthimble without heating its inner end of the thimble kat its point of connection with said heating unit. Said instrument-holding unit is detachably connected with the handle unit which includes switch mechanism longitudinally movable in said handle unit and carrying electrical leads having spring contacts in engagement with the. respective contacts of said vinstrument-holding unit to connect the heating 4element with line wires and arranged to be automatically actuated when the handleis pulled out from its holder to close the circuit through said heating element. and when said handle is replaced in its holder to open said circuit.

-My invention also includes all of the various ,novel features or" construction and arrangement as hereinafter more definitelyv specified.

In the accompanying drawing, Figure 1 is a side elevational View of an electric instrument handle constructed in accordance with my invention; Fig. 2 is a central verticall longitudinal sectional View of the handle and switch elements of the implement shown in Fig. 1 showing a fragment o the heat-directing instrument or needle holder in position for actuation therein; Fig. 3 is a central Vvertical longitudinal sectional View oi said holder with a separable heat-direct- ,ing instrumentor needle attached thereto; Fig. h4 is a transverse vertical sectional view of said implement taken through the handle portion thereof a central Vertical longitudinal sectional view of the outer sleeve of the instrument or needle holder and showing the heat-directing instrumentiormed in unitary relation therewith.

The electric instrument handle `may be divided y ses the tubular struchave itsv outer surface fluted or formed `into a plurality of ilat suriacesand is provided -with the internally disposed threads 2 at its. forward end and the internally disposed screw threads 3 at its rear end with which the .hollowabutment plug 4 serving as` a collar may (be engaged.4 f Y on the line 4--4 in Fig. 2; and Fig. 5is

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The switch unit comprises the core 5, which may be formed of bakelite or other suitable electrical resistance material and which is generally cylindrical in form, being provided with oppositely disposed grooves 6 and 7 extended longitudinally thereof, and having at its forward end the bore 9. Said core 5 is incased by the cylindrical sleeve 10 having the lining 11 :of insulating material into which said core may be forced and retained.

The sleeve 10 is in threaded engagement :at its rear end 12 with the switch block 13 having the enlarged band 15 forming the shoulder 1'6 against which said sleeve 1.0 engages and the shoulder 17 alfording an abutment arranged to engage the forward end of the abutment plug 4. Said switch plug 13 is provided with the ferrule 19 having the abutment shoulder 18 arranged to engage the abutment plug A4 .to iimit the forward movement of the switch unit in the handle unit Aand provided with the iiared terminal flange 20 forming an open mouth 21 merging into vthe bore 22 of said switch lblock 1-3, through which .the leads 23 `and 25 having the .terminal connectors 26 and 27 respectively lead into .the bore of the sleeve 110 and its insulated :ing l1. The lead 23 is -suitably attached at 29 to the spring contact 30, the vspr-ing tang 31 of which is provided with the contact point 32 extended inwardly toward the axis of the implement. The lead '25 is suitably attached at 33 to 'the spring contactl', the `spring Itank 36 of which is provided with the contact point 37 extended inwardly vtoward the Iaxis of the implement in a direc-tion :opposite to the `direction Vof the point 32, :said points being :disposed at relatively diiierent axial positions in said sleeve.

The spring contact F is inwardly bent at 39 to engage in the pocket 40 lof the Slot 6 Ito maintain its axial position therein, and similarly the spring contact 35 is bent inwardly :at -42 'into the pocket 43 in the slot 7 'to maintain its axial position therein, it being noted that when `said sleeve is removed from its threaded engagement with the switch-.block 13, both of the spring contacts '30 and L35 are free to dropout of their respective slots 'i6 and v7 so that they may be readily removed and replaced.

1t will be obvious that Ithe entire mechanism -of the handle maybe separated by removing the abutment plug 4, which permits the switch Vmechanism including the switch plug 13 and parts attached thereto to be slipped from the tubular structure 1., and by removing the sleeve 10 from the Switch-block 13 the -core will be exposed to permit Athe removal of the spring contacts 30 :and 35 and by breaking the joints where said spring contacts are connected at 29 and 33 to the leads 23 and 25, said leads may be conveniently drawn out for inspection, repair and replacement.

The screw threads 2 at the forward end of the tubular casing 1 aiord means for attaching the instrument holder which comprises the body 45 having Vthe nut 46 and the threaded rearward extension 47, which, as shown in Fig. 2, is conveniently engaged with 4the threads 2 of said tubular casing 1 of the handle, and also yhas the forwardly directed tubular extension 49 provided 'at its outer end with the hollow tapering Lshell or cap 50 preferably formed of copper and engaged with the forward end of vthe extension 49 by any sui-table manner as by brazing, said cap 50 being preferably filled with ing element 52, so as to convey hea-t from said a refractory cement 51 in which is embedded the heating coil 52, the terminals 53 and 54 of which are connected with the wires 55 and 56 extended rearwardly through the insulation lling 57 disposed in the forward extension 49 of the body 45, and said wires 55 andv 56 terminate the body 45 :and are respectively 4connected to the contact sleeve 59, which is held in the insulated lining 60 in the body 45 and to the axial rearwardly extending stem contact 61 extending suitably beyond the end of the sleeve 59 and being provided for the greater part of its length with an insulated covering 62 disposed between said stem :contact 61 and the sleeve contact 59 thereby insulating one from the other and extending rearwardly considerably beyond the inner end of said sleeve contact 59.

Referring to Fig. 2 of the drawing it will be noted that when the body 45 of the instrument holder has its threads 47 engaged with the threads i2 of the tubular casing l, the stem contact will be engaged by the lcontact point 32 of .the spring contact 30, `and the sleeve contact 55.9 will be engaged by the contact point V37 of the vspring contact A35 lto form an electric-circuit OO necessary to energize the heating -element'50, 'said circuit being ciosed through the lead 23, spring :contact 30, tang 31, contact point 32, stem contact y6l, wire 56, heating element '50, wire l55, sleeve contact :59, contact point 37, tang 36, spring contact v35, and lead 25.

However, if it is :desired to break the electric vcircuit thus described, :the switch-block and the switch mechanism connected therewith may be longitudinally shifted forwardly with respect to the tubular casing 1 lu-nt-i-l the abutment 1`8 engages the rear 4end of the 4abutment plug 4, in lwhich position the contact point 32 will Ahave been sli-d from I contact lwith 'the surface oi the stem Contact 61 on to the insulated covering 62, .so ythat no current can pass through the handle 'to energize `.the heating element 52. Thus it will be seen, the circuit may be broken by slightly shifting the switch mechanism including the ferr-ule 19 with respect to the tubular casing 1 H20 forming the handle, and these parts, however, may be maintained lin their 'operative position to aiiord a closed circuit by means of the spring tang '65, serving as a detent which has the later- 4ally extending projection A66 arranged to enter the circular groove 67 in the bore of the abutfment plug 4, `.as vshown -in Fig. 3.

As shown in lFig. 3, the `instrument holder is :provided with the external screw threads 70 remote from its forward end arranged to receive .he interna-l screw :threads 71 of the elongated `thimble 72, 'which is -telesoopically disposed about the forward tubular extension 49 of the instrumen-'t holder. said thim'ble for the greater part vof its length being disposed -f-ree from said extension 49 and aifording an annularair space. The forward end, however, of said thimble is provided with a tapering pocket 73 which is arranged to snugly engage the cap 50 ofthe heatheating element '52 to the instrument 75,- which, in the instance shown, is 'a tapered pointed needle removably engaged with the outwardly projecting threaded vstem 76 of the thimble 72.

It will, of course, be understood that this instrument which,'as shown in Fig. 3, is detachable and replaceable, and may be of 'dnierent forms or may be formed unitary with the lthimble if desired, as lshown in the ymodiiication` vin r11-g. 5, wherein 'the renale e2 11a-sits pointed i150 instrument 85 formed unitary therewith and directed forwardly at an angle with respect to the axis of said ferrule and the heating implement to which it is to be attached.

The heating implement herein described is applicable to a variety of uses, and in addition to the pointed instruments herein shown and described, it may be employed in connection with other forms of heating points and cauteries, and such handle may be connected with a similar holder for carrying a mouth lamp for illumination purposes; therefore, I do not desire to limit my invention to the precise details of construction and arrangement as herein set forth, as it is obvious that various modifications may be made therein without departing from the essential features of my invention as defined in the appended claims.

Having thus described my invention, I claim:

1. An implement of the class described, comprising a tubular casing affording a handle, an instrument holder provided with a heating element disposed with its forward end detachably engaged with said handle and having electrical contacts extended into said handle, switch mechanism longitudinally movable in said handle and provided with electric leads arranged to connect electric line conductors with said electric contacts and by its longitudinal movement make or break the electric circuit in said heating element, and an elongated thimble removably engaged with said instrument holder at a region remote from said heating element, but having contact therewith adjacent to said heating element aifording an intermediate region out of contact and providing an air space.

2. An implement of the class described, comprising a handle body, an instrument holder detachably engaged with and withdrawn from the outer end of the handle body and having electrical contacts within the said handle body, a switch body at the other end of the handle body extending within the said handle body carrying electrical supply lines and having spring contacts for engaging electrical contacts of said instrument holder arranged to complete an electrical circuit by a relative longitudinal movement of said handle body and said switch in a direction to increase the length of the handle.

3. An implement of the class described, comprising a tubular casing forming a handle having abutment and retaining means, a switch unit movable longitudinally in said handle and comprising a tubular casing having an insulated lining, a core of insulating material within said lining having opposed longitudinal grooves forming abutments, spring contact members removably engaged in said grooves and bent to engage said abutments to prevent their relative longitudinal movement therein, line leads extended into said casing and removably engaged with said spring contact members, a spring retainer on said switch unit arranged to engage the retaining means on said handle, and an instrument-holding unit having a heating element connected by leads with relatively insulated contacts arranged to be engaged by said spring contact members, one of said contacts having an insulated sleeve arranged to be engaged by one of said contact members when said switch unit is moved forwardly in said handle.

4. An implement of the class described, comprising a handle body, an instrument holder detachably engaged with one end of the handle body and having electrical contacts axially movable within the said handle body, a switch body projecting from the other end of said handle body and extending within the handle body carrying electrical supply lines, said switch body being telescopically movable within said handle body, and means comprising a detent arranged to arrest said switch body in its operative withdrawn position.

ROBERT C. ANGELL.

CERTIFICATE OF CORRECTION.

Patent No. 1,968,867. August 7, 1934.

ROBERT C ANGELL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 80, claim 2, after "switch" insert body; and line 81, same claim, for "handle" read implement; and that the said Letters Patent should he read with these corrections therein that the same may conform to the re-eord of the case in the Patent Office.

Signed and sealed this lith day of September, A. D. 1934.

(Seal) Acting lftsnltitiliggiioziir ot Patents.

CERTIFICATE or ooRREoTIoN.

Patent No. 1,968,867.

August 7, 1934.

ROBERT GT' ANGELL.

It is hereby certifier! that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 80, claim 2, after "switch" insert body; and line 81, same claim, for "handle" read implement; and that the said Letters Patent should he read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this llh day of September, A. D. 1934.

(Seal) Acting [lritiligrfilggr of Patents. 

